Road safety devices, such as red triangles, to alert motorists to stationary vehicles are known. US2003196361 discloses a collapsible triangular warning sign that can be placed on the road at a distance in front of or behind a stationary vehicle to allow passing vehicles sufficient time and distance to take avoiding action. It is, however, necessary for these signs to be placed at some distance from the vehicle for optimum effectiveness. This requires the user to walk away from the vehicle in order to position the sign, often on a busy road and in poor visibility conditions. The user must also remember to recover the sign once the vehicle has been repaired or removed.
Some cars today include a red triangle in the boot which is visible when the boot is left open. The triangle is small compared to the car and is visible only when the boot is left open, which presents a security risk.
Other methods of alerting motorists to a stationary vehicle include using the hazard lights and/or side lights to signal the vehicle is immobile. However, these lights must be powered by the car battery and are therefore only usable for a finite period of time.